My memory is a bit fuzzy... how did Despres look with Letang last year? IIRC, didn't it force Letang to play "babysitter" a bit more, and by extension, force him to play a simpler, defense-first game (shocking for a defenseman, I know).
I hate the idea of a Letang/Niskanen line, but I also hate the idea of breaking up Maatta/Bort, and to a lesser degree, Martin/Orpik. Still think Niskanen is the odd man out, but with Scuderi going down for months (presumably), it reduces the chance Shero deals anyone on the blueline from "cold day in hell" to "literally zero".